Amateur television was one of those things that
always intrigued me - maybe it's the childhood fantasy of being
on TV, or the thought of owning your own "TV station".
Whatever the original interest, there is something special about
sending pictures to other people - just ask the millions of
people who swap their photos over the Internet every day.

ATV represents the ultimate in "picture
swapping" - live, broadcast quality (depending on the
camera, etc) moving pictures. But with that comes the perception
that ATV is expensive and only for the well off ham. Nothing
could be further than the truth, as I have discovered. Yes, you
can spend tens of thoudands of dollars on an ATV studio, cameras,
transmitters and the like, but like most facets of amateur radio,
you don't have to.

What got me started in ATV was the discovery
that I had enough equipment sitting in the shack to receive not
one, but 3 bands of amateur television - namely 70cm AM, 23cm
FMTV and 13cm FMTV. Of this gear, only one item, a Pace satellite
TV receiver which cost all of $10 at a hamfest, was bought
specifically with ATV in mind!

So what does a $10 ATV receive setup consist
of? Well, the first (and arguably most important part) is a TV
set, or a VCR/monitor setup which is what I have. My monitor was
surplus from work, and I saved it from the scrap heap. It also
doubles as a second TV when I want to watch the telly in the
shack! The VCR is a spare VCR I had lying around, but if you're
not that lucky, you can look around for a secondhand VCR which
won't play tapes. The tuner section usually will still work. This
Tv or TV/VCR setup is the most important past of an ATV station,
and also, by itself, is capable of receiving ATV transmissions in
the top part of the 70cm band (in Australia, the upper ATV
channel is at 444.250 MHz - or around "channel 16"
UHF). For an antenna, the existing domestic UHF TV antenna will
suffice for strong signals, but a dedicated antenna should be
considered.

While AM (or more correctly, VSB) modulation,
the same as used for broadcast TV, is used on 70cm, FM is
favoured on the higher bands. Here in Melbourne, the 23cm input
to the ATV repeater uses FM, and I'm not aware of any AM TV
activity on 23cm or higher, all the hams I know use FM. Normal
TVs don't receive FMTV well, so some form of converter is needed.
While the ideal solution is to build a dedicated FMTV receiver,
which will cost only around $100 and several hours of one's time,
it's a fortunate coincidence that many satellite TV systems used
a LNB at the dish, followed by a receiver which had a tuneable IF
that covered at least 900-1400 MHz, sometimes as wide as 750 -
1750 MHz. 23cm ATV at 1250 or 1280 MHz falls right in the middle
of the satellite receiver IF passband, and analogue satellite TV
in its basic form is FM! These old satellite receivers can be
bought for $10 at hamfests, and with the addition of a preamp,
will receive 23cm FMTV transmissions. Because FMTV uses less
deviation than satellite TV, reception won't be quite as good as
that obtained by a purpose built receiver, but some satellite
receivers can be modified to improve their performance. Satellite
receivers also have DC power supplied on their input connector,
which can be useful for powering masthead preamps or converters
for other bands (but if you directly connect an antenna, be
careful!). As for an antenna, a loop Yagi is quite popular on
23cm.

Once one has the capability to receive 23cm
FMTV, adding other bands is quite easy, as all that is needed is
an appropriate converter. If you're lucky and have a Pace
satellite receiver, or another FM receiver capable of going down
to 750 MHz, 13cm reception can literally cost nothing, or very
little! Some old Conifer MMDS TV converters were designed to
convert 2200 MHz to the 500-600 MHz portion of the UHF band, and
have a 1657 MHz local oscillator. The same converters will also
convert 2414 MHz to 757 MHz and 2438 MHz to 781 MHz without
modification. What's more, they work well off the satellite
receiver's DC power - truly plug and play! :-) As the converters
come with their own grid reflector (mine has an 18 dBi antenna),
nothing more is needed for 13cm. Unfortunately, the newer
converters that were used for Galaxy pay TV and the like use a
1951 MHz local oscillator and aren't as easy to use for FM ATV
(you would need either an FM demodulator for 460-480 MHz or
upconvert to a satellite receiver IF). However, if anyone nearby
uses AM TV, the Galaxy converters will put these transmissions in
the lower part of the UHF band. Now your ATV receive setup covers
3 bands for very little expense - the most expensive parts are
the 23cm antenna (homebrew) and interconnecting cables.

It's possible to go further. I'm looking for an
old Ku band LNB, which can be modified to receive 10 GHz ATV, in
conjunction with a satellite or other 23cm receiver. These things
are appearing at hamfests these days for very reasonable (around
the $10 mark) prices. I already have dishes for this band, but
surplus dishes should be obtainable, or a dish can be home brewed
(I have heard that mild steel woks often have a near paraboloid
shape).

That takes care of the receiver. As for the
transmitter, the easiest way to go here is build a kit. For VK
amateurs, Mini Kits in Adelaide have a range of VHF/UHF/microwave
kits, including ATV transmitters and receivers for most bands
from 70cm to 10 GHz at reasonable prices. Settung up an ATV
transmitter does cost a bit more, in the order of a few hundred
dollars, mainly because of the cost of obtaining a reasonable
amount of power on the microwave bands. But it's still well
within the reach of most amateurs, provided one is prepared to
spend a bit of time and effort constructing the equipment (ahh,
the smell of burning flux! :) ).

Finally, there's the matter of signal sources,
namely cameras, VCRs and other video devices. There's a number of
old cameras around. I have an old home porta pack, which consists
of a colour video camera and a VCR. It requires a lot of light to
operate, but still works. The VCR also works, so I can make
videos while away from the transmitter and play material recorded
previously to air. I would prefer a more modern CCD camera, as
these work better in low (i.e. indoor) lighting, have better
picture quality and are more compact. There is also a kit around
for a PC driven character generator, which would be useful for
displaying callsigns and other information. It's also possible to
construct relatively inexpensive character generators for
portable use.

ATV in this shack is still in its early days,
but I hope I've dispelled the myth that it has to be expensive
(of course, it can be!), and is within the reach of most
amateurs, with a little effort. SWLs are in an even better
position. Most capital cities and some regional cities have an
ATV repeater, and many of these can be received with an ordinary
TV set. For those in Melbourne, look at the extreme bottom end of
the UHF TV band for any signals (actual frequency is 444.250
MHz). You may be able to receive the VK3RTV repeater if someone
is on air. I'd suggest trying at 8PM on a Wednesday evening, when
APC News is being broadcast (i.e. when there is a known signal).
Sydney viewers can try between 7PM and 8PM, when the local ATV
club starts a broadcast, followed by the VK2 Division of the WIA.
I think the frequency is the same as that used in Melbourne, but
am not sure.